merger (n.)youdaoicibaDictYouDict[merger 词源字典]
1728 in legal sense, "extinguishment by absorption," from merge (v.), on analogy of French infinitives used as nouns (see waiver). From 1889 in the business sense; not common until c. 1926. General meaning "any act of merging" is from 1881. [merger etymology, merger origin, 英语词源]